﻿    #include "base64.h"  
    #include <iostream>  
    #include <ctype.h>  
    static const std::string base64_chars =  
                 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"  
                 "abcdefghijklmnopqrstuvwxyz"  
                 "0123456789+/";  
      
      
    static inline bool is_base64(unsigned char c) {  
      return (isalnum(c) || (c == '+') || (c == '/'));  
    }  
      
    std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {  
      std::string ret;  
      int i = 0;  
      int j = 0;  
      unsigned char char_array_3[3];  
      unsigned char char_array_4[4];  
      
      while (in_len--) {  
        char_array_3[i++] = *(bytes_to_encode++);  
        if (i == 3) {  
          char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
          char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
          char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
          char_array_4[3] = char_array_3[2] & 0x3f;  
      
          for(i = 0; (i <4) ; i++)  
            ret += base64_chars[char_array_4[i]];  
          i = 0;  
        }  
      }  
      
      if (i)  
      {  
        for(j = i; j < 3; j++)  
          char_array_3[j] = '\0';  
      
        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
        char_array_4[3] = char_array_3[2] & 0x3f;  
      
        for (j = 0; (j < i + 1); j++)  
          ret += base64_chars[char_array_4[j]];  
      
        while((i++ < 3))  
          ret += '=';  
      
      }  
      
      return ret;  
      
    }  
      
    std::string base64_decode(std::string const& encoded_string) {  
      int in_len = encoded_string.size();  
      int i = 0;  
      int j = 0;  
      int in_ = 0;  
      unsigned char char_array_4[4], char_array_3[3];  
      std::string ret;  
      
      while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {  
        char_array_4[i++] = encoded_string[in_]; in_++;  
        if (i ==4) {  
          for (i = 0; i <4; i++)  
            char_array_4[i] = base64_chars.find(char_array_4[i]);  
      
          char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
          char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
          char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
      
          for (i = 0; (i < 3); i++)  
            ret += char_array_3[i];  
          i = 0;  
        }  
      }  
      
      if (i) {  
        for (j = i; j <4; j++)  
          char_array_4[j] = 0;  
      
        for (j = 0; j <4; j++)  
          char_array_4[j] = base64_chars.find(char_array_4[j]);  
      
        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);  
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);  
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];  
      
        for (j = 0; (j < i - 1); j++) ret += char_array_3[j];  
      }  
      
      return ret;  
    }  